Remote Sensing Workshop – Aberystwyth – May 2009

1. Remote Sensing Workshop – Aberystwyth – May 2009 The Interplanetary Scintillation (IPS) Data Format: a Brief Summary Following the Toyokawa IPS Workshop Mario M. Bisi(mmbisi@ucsd.edu) Center for Astrophysics and Space Sciences, University of California, San Diego, 9500 Gilman Drive #0424, La Jolla, 92093-0424 CA USA http://www.spacephysicist.com/

2. So, what’s the problem??? The STELab antennas of Fuji (top left), Sugadaira (top middle), (new) Toyokawa (top right), (old) Toyokawa (bottom left), and Kiso (bottom middle); and Ooty (bottom right) (Courtesy of http://stesun5.stelab.nagoya-u.ac.jp/uhf_ant-e.html, B.V. Jackson, and P.K. Manoharan) Others can also include: EISCAT/ESR, northern Scandinavia; MEXART, Mexico; MERLIN, UK; Pushchino, Russia; MWA, Australia; and LOFAR, Europe… … …

3. Toyokawa IPS Workshop – October 2007

4. Abstract At the interplanetary scintillation (IPS) workshop in Toyokawa, Japan, late-October 2007, initial discussion took place on a fixed common format for IPS data. The discussion ranged from what the programming structure of a common format should be (including the choice of coordinate systems etc…) to what data products should be included in this format. The driving goal was to allow these data to be more-easily shared among those directly-related to IPS work as well as to those not in the field, and eventually for multiple-analysis IPS methods. Here, I give a brief summary and agreed-upon aims/goals of the discussions which took place at the Toyokawa IPS workshop and through relevant follow-up communications. These are intended to serve as a starting point for the newly-re-opened topic at Aberystwyth.

5. Common IPS Data Format (CIDF) (1) • For better collaborations between ourselves (primarily the IPS community in this case) and any hope of anyone else being able to use IPS data, we need a set agreed-upon unified data format. • Many discussions via E-Mail regarding ideas to the format took place prior to and during the Toyokawa Workshop, with some continuing between various member of our community following. • The ability to apply our own tools/techniques to any IPS data from any IPS-capable system adopting this data format (hopefully all). And …

6. CIDF (2) • The primary naming convention should be in the J2000 epoch for source names. • In addition, B1950 and 3C/CTA catalogue names should also be provided (Mario proposed this as the best compromise, Bernie and others thought it was unnecessary; following Tuesday afternoon discussions this week here at Aberystwyth I think we agree this is both necessary and helpful) • The primary set of coordinates however should be RA and Dec, again in J2000 epoch. And …

7. CIDF (3) • Data should be in a science-ready format, but with varying levels of analyses (also discussed briefly on Tuesday this week). • Likely experimental format to be FITS (since many IDL/SSW routines and other instrumentation uses this format already) or HDF5 (since this appears to be more appropriate for our needs). • We need a unified IPS source list with comments on reliability and scintillation likelihood at different observing frequencies and varying distances from the Sun (touched upon Tuesday this week), source strength at each frequency and source size (as noted in the Hick et al. talk given by me on Wednesday morning this week). And …

8. CIDF (4) • Format should be primarily ASCII text with rows and columns (later to be pinned down exactly) but should include in addition to source names/coordinates various other information. Here are some of the examples discussed as being necessary: • P-Point distance from the Sun (and observing elongation angle); • some form of coding name for each observing system; • some form of coding name for the individual antennas from each particular system; • some version number/level scheme to distinguish how far the data have been analysed; And …

9. CIDF (5) • the obtained velocity value(s) and perhaps some form spread/confidence; • the scintillation level (and g-level) where available; • some method of allowing single- and multi-site analyses; • some method of allowing multi-stream values; • should try to include the time series, cross-correlations/spectra, perhaps images of such, and experimenters comments regarding the observation. • etc… And …

10. As An Aside (data are courtesy of Aberystwyth): EISCAT 3D tomographic reconstruction of April-May 2007 (see Gareth Dorrian’s talk this morning following tea/coffee – Thursday) using the main peak velocity estimates from the cross-correlation functions with the UCSD time-dependent model. Velocities shown in the movie are restricted to between 200 km s-1 and 400 km s-1 which clearly show the co-rotating streams. Some form of transient velocities may also be seen and these warrant further investigations. Watch this space!!!

11. And A Little More Aside:

12. And A Final Aside:

13. I digress… …now back to the point at hand…

14. Summary • We NEED a unified CIDF! • We want a simple set up so as to encourage non-IPS specialists to take advantage of this very useful technique. • We want to have some form of ASCII summary tables with the more-detailed information/analyses embedded (e.g. as with FITS files where you may get various images in the same file and summaries in the headers; same can likely be achieved with the HDF5 format as discussed in Toyokawa). • And finally… WE WANT IT NOW?!  Now over to Leonid I guess… … …